The present invention relates to a method of closing a container. More particularly this invention concerns the fabrication of a filter.
It is known to make a filter by mounting a filter element tightly inside a container and then sealing a cover over the open side of the container. This sealing is frequently done by means of a two-component adhesive of the epoxy type. Thus immediately prior to the application of the cover to the rim of the container this rim is coated with the adhesive in liquid or runny condition. Then the two elements are mounted together and, if desired, the rim is bent or crimped over the edge of the cover. Such a method produces an extremely tight and strong bond.
Nevertheless, this arrangement has the considerable disadvantage that it is relatively messy. When used in a production line the epoxy adhesive frequently dirties the conveyor belt and other equipment. Since such epoxy dries to an extremely hard condition deposits of this adhesive are extremely hard to remove and bothersome. Furthermore this method requires a relatively quick operation, as if the epoxy is allowed to dry it is impossible to form a proper bond between the two elements. Another disadvantage is that the epoxy does not harden rapidly, so that it is necessary to set the freshly sealed filters aside and only test the seal at a later time. Obviously, this latter disadvantage greatly slows production rate.